Electronic accumulator



March 2, 1954 c. F. RENCH 2,671,171

ELECTRONIC ACCUMULATOR Original Filed Jan. 7, 1950 INVENTOR CARL F. RNCH av Wm M1 HIS ATTORNEYS ONDNIDIO Q'ION-O I IOBV they' reduce thenumber Patented Mar. 2, 1954 orrics 2,671,171 ELECTRONIC ACCUMULA-TORCarl F; Rench, Troy,

tional Cash Register a corporation of Mary Original application, January7,

now Patent No. 1', 1952. Divided and t Ohio, assignor to The Na-Conipany, Dayton, land Ohio,

1950,, Serial No. 2,591,008, dated April his application March 14, 1951,Serial No. 215,485

5 Claims. (01. 250-2.7')

This invention relates to a novel electronic accumulating apparatus inwhich a plurality of electronic devices are provided in eachdenominational order, and are interconnected to count in the decimalnotation and to represent digits in the decimal notation by combinationsof conducting and non-conducting conditions of the electronic devices.

This is a division of United States application Serial No. 137,311,which was filed on January 7, 1950, and which issued April 1, 1952, as aPatent No. 2,591,008.

Each denominational order of the accumulator utilizes four trigger pairswhich can be operated alternately to stable states, or on and offconditions, in response to impulses, which trigger pairs are connectedin cascade. Input impulses are applied to the first trigger pair of thecascade, which pair, on each second operation thereof will send anoperating impulse over the cascade connection to the second triggerpair- In like man.- ner the second trigger pair will send impulses overthe cascade connection to. the third trigger pair and the third triggerpair will send impulses over the cascade connection to the. fourthtrigger 13311.

In addition to the cascade connections the device has a direct-currentcircuit which connects the fourth trigger pair to the biaspotentialsupply of the second and third trigger pairs. This connectionenables; the fourth trigger pair to control the bias on 'the second andthird triggerpairs in such a, manner that when the fourth. triggerpair-is in, one of its conditions of stability the bias on the secondand third trigger pairs will be such as to permit these pairs to operatenormally as trigger pairs; but when the fourth trigger pair is in itsother condition it will change the bias to cause the second and thirdtrigger pairs each to make an additional operation and incidentally willprevent these two trigger pairs from making further trigger operations.

A; further control circuit from the first trigger pair to the fourthtrigger pair becomes effective after the fourth trigger pair has causedthe secondiandi third trigger pairs to make an extra operation and willcause an additional operation of the fourth trigger pair to restore thesecond and third trigger pairs to further normal operation as triggerpairs.

These: novel circuit arrangements which enable a direct -current controlto be utilized to cause additional operations of the second and thirdtrigger pairs have distinct advantages because of circuit componentsnecessary for the required operation by omitting rectifiers, capacitorsand other such circuit components which would be necessary ifimpulsetype of control as distinguished from the directcurrent type wereused. Further, the arrangement using the direct-current type of controlis more stable in operation and less susceptible of improper operationdue to erroneous feed-back of impulses over the control circuits, whicherroneous feed-back occurs when capacitors are used in impulse-typecontrols unless proper precautions such as rectifiers or decouplingtubes are used.

It is an object of the invention to'provide an improved electronicdigital accumulator of the eombinational type which uses direct-currentieed-back circuits and related controls to enable accumulation in thedecimal notation to be accomplished using four trigger pairs.

A further object of the invention is to provide a decimal accumulator,of the type which uses four trigger pairs in cascade, with novelcontrols which require a minimum of circuit components other than thosenecessary for the trigger connections and cascade connections.

A further object of the invention is to provide a decimal. accumulator,of the type which uses our trigger pairs in cascade in eachdenominational order, with novel controls which vary the bias on certaintrigger pairs to cause additional operations thereof as required incombinaticnally representing certain digits of the decimal notation.

With these and other incidental objects in view, the invention includescertain novel features of construction and combinations of parts, apreferred form or embodiment of which is hereinafter described withreference to the drawings which accompany and form a part of thisspecification.

The drawing shows a circuit diagram of the units denominational order ofthe accumulator, including tens transfer means and coupling meansthrough which entries can be made into the order and shows schematicallya digit-manifesting means.

In order that the invention may be explained more fully, a preferredembodiment of the invention will be described, in which descriptionvalues of potential and circuit elements, such as resistors andcapacitors, will be given and types of tubes will be specified. It isnot intended, however, to limit the invention tothe embodimentdescribednor to limit the circuit values and tube typesto those specified,because these are mere- 1;; selected as illustrative. It is obvious thatother potentials and/or other similar tube types can be used and thecircuit values of resistance and capacitance can be adjusted to maintainthe pro er relation between the various parts of the circuits.Throughout the circuit diagram, the heater elements for the tubes areshown conventionally.

The drawing shows one of the accumulator but as many provided asdesired. Each denominational order includes an electronic couplingdevice, an electronic tens transfer means, and a plurality ofinterrelated electronic devices capable of accumulating in the decimalnotation and representing, in combinational form, the units digit ofsaid accumulation.

The particular denomination shown in the drawing is the unitsdenominational order of the accumulator.

The coupling device is shown as a twin triode, tube 220, preferably ofthe type sold by the Western Electric Company under the type designation2651, though, as will appear later, only one of the tricdes is utilizedin the units order, the one for coupling the order of the accumulator tothe corresponding denominational output conductor of an impulsegenerator. In the embodiment shown, there are no tens transfer entriesto be made in the units denominational order of the accumulator, andaccordingly the other of the triodes is not used to control entriestherein.

Tube 220 has both of its anodes 22l and 222 connected together overpoint 223 and resistor 225 denominational order of 100,000 ohms toconductor 225, to which a potential of +200 volts is applied at terminal226, and has its cathodes 221 and 223 and its shield 229 grounded.

Grids 230 and 23! have biasing potential supplied thereto from a biasingpotential supply circuit which extends to ground from conductor 232, towhich a potential of 108 volts is applied at terminal 233, over resistor234 of 100,000 ohms and resistor 235 of 15,000 ohms, grid 230 beingconnected over point 235, and resistor 231 of 47,000 ohms to point 238in the bias potential supply circuit, and grid 23! being likewiseconnected over a resistor 240 of 47,000 ohms to point 24! in the biaspotential supply circuit. Point 24! is connected to ground over astabilizing capacitor 2:12 of 500 micro-microfarads. The potentialsupplied to the grids normally biases both halves of the tube tocut-off.

The units denominational input conductor I22 to which positive potentialimpulses may be supplied by any suitable impulse generator, one of whichis disclosed in said application, Serial No. 137,311, is coupled overcapacitor 243 of 250 micro-microfarads to grid 230, which controlsconduction between anode 22! and cathode 221 of the left triode in thetube 220. Whenever an impulse of an impulse train is impressed onconductor I22, it will be efiective to cause the triode, which iscontrolled by grid 230, to conduct and produce a potential drop at point223 due to resistor 22% in its anode circuit.

In the units denomination of the disclosed embodiment of theaccumulator, there will be no tens transfer entries from a lower order,consequently grid 23L which controls the right-hand triode of the tube220, will have no impulses applied thereto, so this triode of the tubewill remain biased to cut-off.

The potential drops which are produced at point 223 when conductionoccurs in the tube are orders may be used to provide negative impulsesto operate the interrelated devices of this denominational order foraccumulating amounts. The interrelated devices consist of four triggerpairs connected in cascade and with novel direct-current feed-backcircuits and auxiliary controls to enable the four trigger pairs toaccumulate values in the decimal notation and to represent the variousdigits of the notation by difierent combinations of on or off conditionsof the trigger pairs.

As is well known, an electronic device known as a trigger pair consistsof a pair of electron discharge tubes having interconnectionstherebetween to control their operation so that, at any given time, oneof the tubes is conducting and the other tube is non-conducting, and theact of changing the conducting condition of one of the tubes will causethe conducting condition of the other of the tubes of the pair tochange. With the circuit constants to be given herein, the trigger pairswill be relatively insensitive to positive impulses but will respond tonegative impulses, so that a negative input impulse applied commonly tothe tubes of the pair or to the conducting tube of the pair will causereversal of the conducting and non-conducting condition of the tubes.The trigger pair may be made up of two separate tubes; however, in orderto provide a more compact device, each of the cascaded trigger pairs inthe disclosed embodiment of the invention is formed by interconnectingthe two halves of a twin triode type of tube, preferably of theaforementioned 2C5l type.

The first trigger pair of the cascade will be that marked A, the secondtrigger pair will be B, the third trigger pair will be C, and the fourthand final trigger pair of the cascade will be D. The trigger pairs willbe considered in their "011 condition when the left triode of thetrigger pair is conducting and in their oii condition when the lefttriode of the trigger pair is in non-conducting condition. The manner inwhich the trigger pairs represent the various digits can be seen fromthe following table, in which 0 designates the off condition and X"designates the on condition of a trigger pair.

Trigger pair A is the first trigger pair of the cascade and is operatedby impulses impressed thereon from the coupling device, tube 220. Theleft triode 245 of the trigger pair has its anode 246 connected overresistor 241 of 100,000 ohms to the +200-volt conductor 225 and has itscathode 248 connected directly to ground.

Similarly, the right triode 250 of the trigger pair has its anode 25!connected over resistor 252 of 100,000 ohms to the +200-volt conductor225 and has its cathode 253 directly connected to ground.

Grid 255 of the left triode 245 a negative bias supply over resistor 252of 100 ohms, point 256, resistor 25'? of 510,000 ohms, and conductor232, to which a potential of l08 volts is applied at terminal 233. andalso is coupled to ONOMOMOMOMO oMNNMooMMoo OMMMMNMQOOO tcxoooooooo isconnected to thesanode 2251. got: 'thelrightrtriode 250 oyerraarretework containing the :resistonr258 and resistor:259

f '?:'200,0001 ohms; resistorr 258 being :shuntedby capacitorrZGll of:150 micro-microfarads. Ina similarrmanner; the gr-R1263: of:the righttriode 250 isrconnectedto the-negative bias :supply-over resistor: 2600fi100'i0hms; point1264, resistor 265 of.:f510,000ohmspand-rtoconductor'i't, Whichis connected-over; a: reset switch. 255? rtoterminal 233i. Gridt263rissalso coupled to. the anode-2&5 Oflth 'lefttriode; 2 lzoversa network containing theresistonZBS 1 and resistor "269015,200,000 ohms, resistor.:2 69 being shunted by capacitor 2 I nor v150microemicrofaradsa Roints :256 and .2 E4 inythe bias supply circuitsfori'theagrids'255 andi263zare coupled, respec+ tively, over capacitors275' and l 276 :of micromicrofarads; to a' conductor? 2:17, thence.over' resistor: 218; of 47,000 ohms-t tozthe point .279 in theanodezcircuitiof the coupling-device, tube 220.

With. thercircuit constants given, trigger pair Ar vwill.,;.beresponsive. to; negative impulses and willreversetheiconducting status;of the-:triodes thereinceach time a negative impulse impressed on::thegrids of theitriodes. Accordingly, the trigger pairtwill reverse itsconduction status each timethe coupling device responds toan impulsefromythe impulse generator and sends a negative impulse to;the V pair.

Trigger-pairB; which is the-second trigger. pair of-ithe1 cascade, is,cperatedto reverseithe conductive condition ofithe-triodes therein inresponses; to. an; impulse; impressed; thereon. from trigger pair A whenthat pair goes from its on condition to its: offcondition; Trigger; pairB is 1 alsogoperatedgfrom v its ofi;. condition to its on? conditionjnresponsextozanovsl direct-curs rent, feedback connection from, trigger:pair D. in a manner to be explained-;more:.fully herein after: Theanodes 280, and 28I, respectively, of the .lefttriQdeHZBZ andthe righttrioderzsii of this :pair'are connected over resistors zfl l'and 285 of100,'000 ohms, respectively; tothe +200- volt: conductor 225;and the.cathodesiare, con:- nected'to ground.

Grid' 286 of thealeft triode282fis connected oyer-"resistor2901of 100ohmstozpoint 281i in: .a bias; potentialv supply resistance :network:This network extends from conductor 232; togwhichapotentiaLofir-illltvoltsgis applied; over;resistor 288; of ;390,000.ohms,- point-i287; andjoverrresistol' 293; of;'3 90,000 ohms; and:conductori zsl; oi; the novel; directicurrent' feed-back; circuitto theanode of the right triode of'trigger pairllandene ablesithe. bias; on.grid;286 to,,be variedaccording tozthezrpnif and off? conditionoftriggerzpairrD in aimanner to; beiexplained morefully hereine after.Grid; 2.86.is;;a1so :.coupled;toithesanode,172.8 I

0mm rightittriode zzfigoyer a; network contain"- ing :the:.resistor;.290 and resistor-.19 If arc-390,000 ohms, resistor 291,being:shunted;bycapacitor 2520f 15.0 'micr0' -'micr0f.arads:..

Gridr295. of vjthe. right triode. 203. is.:connected tcsthe :negatiye;bias:- supply; by-being 1 connected oyerresistor 2S0 ;of 100 ohms, point2M; andre sistor 298 of 510,000 ohms to, conductor 266.- Grid 295 is.alsoicoupled. to :the sanode: 280 .:oi the left triode.282 over theresistor 290.;and.resistorptfiil ofi1390,000-7ohms; resistor-1300 beingshunted by 'a capacitor Iof 1.150 mioroemicrofarads.

Point; 28;! in;the; bias; supply circuit: for grid 2.B6 .:is;;connectedover capacitor '305'ior1253microe microfaradsgandpointzfiietozccnductor3116; and

thencesoverresistom 354;; of 1.54:7 g000zfiohmssltozthe anode 25! of therightrtriodeir'iflioiftrigger* pair Aim Peinmsr in;theebiasisupplycircuit'rorrgrid:

295 is also COUPIBd-QIJOQ conductor 30B;overca:'s caa pacitor-30l oL 25i-imicro-v'miorofaradszu The bias applied .to-the grids of triggerpainB'issuch that each :time trigger-pair A is operated to its::oflfcondition: and its righttriode 250 conducts; the negative.impulsewhichriis sent over capacitors 304' and301 to thesgrids 286: and "295 offthe-trig= gerJpairB will ,causeca reversal of :the;. conductingcondition; vof the triodesz Trigger. pairzC, which is' the-third triggerpair o'-'the:cascade, iszoperated to reversewthe con;- ducting:condition :of'; the etriodes therein: in response to an" impulse fromtrigger:pair ::B-; when that: pair goes from its on: condition to: itsdiff-condition;v Triggerrpair C also: has-postential applied to the gridof: its "left triode from a resistance network which includes resistor;308; of 390,000; ohms; and 'theeconductorw 294' oft-"the directecurrentfeed+baclz circuit :from" the anode of therightJtriode-iof :trigger pairD, whichtcire cult is: efiective to: cause; trigger pair C to: beoperated; from its;oif.i condition .toits ontcone dition; when triggerpair '1)... is; turned to its "on?! condition; in a manner, tobe.explained: more fully-hereinafter; The ;circuit arrangement-land circuitconstants forstriggertpair --C are identical with those oftrigger.:pair;B and willnot besres peated.v

Trigger pair 13, which is the last trigger: pair in the; cascade; is:operatedircnriits -:ofi condition. toits on COHditiOIITbYdmDUISESimpressed on its right triode from triggerzpair -C.'and"is ='alsooperated from its :on! "condition: .to 'itsofii 0011-;- dition; inresponse; to; impulses directly: applied to the grid of itsleft-triodeirom triggerk pair'A-a Trigger 3 pair :11 is; eife'ctive;whens-in on condition; toicause triggerpairs B and Cto bet-turned frorn;0i'1" to njf-overrtheznovel direct current feedeback circuits-thereto;Trigger pair D, is also efiective:toHsenduaniimpulse stop a.- tenstransfer mean-Ste.preparezitionav tens transfer operation;

The: left; triode 3i 0: of:trigger 'pair -D ha'SagitS anode ,3! ICOIIIIGCIZGGTOVEI resistance:3 I 21of 100,000 ohmsL to: the 3+2005V01l3:ccnductora225 andhas its cathode connected: to: ground. In" this;trigger pair; the sright: triodesii 8 ;has its:- anode 31 1. con-1nected over resistor 3I8 iof.'j80,000; ohms :tcthe +2il0svolt"conductor? 2'25; andih'astits cathode connectedztoiground'.

Grid;325:of therlefttriode 3! tfis connected to thesnegative bias'supplyovert resistor; 3281 of ohms; point 3 25 resistor 32? of 510,000 ohms;and conductor 232, and. is -also coupled to the anode 31'! of the righttriode 3 I 6 over the resistor-328 andresistor- 3 2. 9 of "390,000 ohmsresistor 3 29 being shunted by capacitor 330; of 5001. miCI'O:miCIO."faa 'Y Y similarly,- the.; rid. 33.5 orithezriglitgtrioner3i! .6 is.connected' tolthesnegativebias supply over re.-.. sistorfitoi100-0hms,point 336, resistor 33'! of 510,000.0hms, and. condu.ctor; 266., Grid3351is-also coupled to the anode SII oftheileititriodeijlfl over the;resistor v 3.38; and resistor 339; 01390 000 ohms;resistor1331heing-shuntedlay-capacitor; 340 of micro-microfarads. I v.

The-;.point 35 in;.theibiaszpotentialsupplyacircuitzfor.gridrSSz'irofgthe-right:triodeiszcouplediovercapacitorrltfii; of;25:microamicrofarads, to the anode; ofsithesriglit"triode of I trigger pair: C. and receives negative eimpulse therefrom-.each' time change-from aadigitrepresentation: of "7" to #331 Thiszneg'ativerimpnlsevwhich is applied "to: grid 335will cause trigger pairD to go from its off condition to its on condition.

The point 325:: in the potential supply circuit to grid 32% of the lefttriode is connected over capacitor 33!, of 25 micro-microfarads,resistor 332, of 47,000 ohrns, and conductor 333 to point 393 in thecircuit from trigger pair A to the grids of the triodes of trigger pairB. The negative potential impulses which are sent from trigger pair A totrigger pair B when trigger pair A is turned from on to on are alsoapplied over the conductor 333, resistor 332, and capacitor 32%: to thegrid 325 to turn trigger pair D from on to off. As is seen from thechart given earlier herein, trigger pair D is in ofi condition for alldigit representations except 8 and 9, so that the impulses from triggerpair A when it changes from a representation of l to 2, from 3 to 4,from 5 to 6, and from 7 to 8 will not be effective to cause trigger pairD to change its conducting status. The only impulse from trigger pair Awhich is effective to turn trigger pair D from on to off is that whichis generated by the turning of trigger pair A from on to off in changingfrom the digit representation of 9 to 0.

The manner in which trigger pair D exerts its control over the triggerpairs B and C through the direct-current feed-back circuits, and iscontrolled to enable this control to be used, is as follows:

As is clear from the chart given earlier herein, trigger pair D is inits ofi condition for digit representations of 0 to 7, and, when triggerpair D is in off condition, its right triode will be conducting andanode 3 will be at about volts potential due to the drop across itsanode resistor 3 i 8 and to the low impedance of the conducting triode.The potential of the anode under this condition will be reflected on thepotential of the grid 28% of the left triode of trigger pair B and thecorresponding grid of trigger pair C, through the direct-currentfeed-back circuit and their respective resistance networks, to givethese grids a normal bias which will allow the trigger pairsrespectively to operate in response to negative impulses from triggerpairs A and B, as is necessary in the combinational representation ofthe various digit values.

When trigger pair D goes to its on condition from ofi condition, in thechanging of the representation from 7 to 8, the right triode 3l6 willchange from conducting condition to nonconducting condition, and thepotential of anode 31'! will rise to a sufficiently positive potentialthat, when it is reflected back. on the grids of the i.

left triode-s of trigger pairs B and C over the diroot-current feed-backcircuit, it will cause the steady bias potential of these grids tobecome positive enough to cause the left triodes of these trigger pairsto become conducting and, through the trigger connections, cause thesetrigger pairs to go from their oii condition to their on condition asrequired for the combinational representation of the digit 8.

Trigger pairs B and C will remain in their on condition when thecascaded trigger pairs represent the digit 9.

When the impulse is applied to the cascaded trigger pairs to change therepresentation from 9 to 0, it will first cause the trigger pair A tochange from "011 to off, and, in turning off, trigger pair A will send anegative impulse to trigger pairs B andD, the impulse on trigger pair Dchanging the pair from on to .off and thereby removing the positive biaswhich was supplied to the grids of the left triodes of trigger pairs Band C. With the reduction of this positive bias on the left triode oftrigger pair B, the

remaining eiiect of the negative impulse from' trigger pair A causestrigger pair B to turn from its on condition to its ofi condition, andthe impulse from trigger pair B, as it turns to oil, will turn triggerpair C from its on" condition to its off condition. The impulse fromtrigger pair C will not be efiective to cause trigger pair D to go fromits oii condition to its on condition, because the above changes in thestatus of trigger pairs B and C is so rapid that the impulse fromtrigger pair C will be impressed on trigger pair D before the chargesstored on capacitors 330 and see, in the turning of trigger pair D fromon" to on, have been dissipated.

It is to be noted that, with the novel directcurrent feed-back circuitsand the associated controls, the four cascaded trigger pairs can beoperated to accumulate values in the decimal notation in a very simplemanner. The feed-back and controls of the denomination are effected withthe minimum of additional components, since two resistors resistors 293and 3&8 in the feed-back circuits-are the only components required inaddition to the usual trigger and cascade connections. The novelcontrols eliminate the need of additional capacitors, rectifiers, orother control tubes which previously have been required to enable thedesired results to be obtained. Consequently the novel arrangementresults in a smaller and more compact denominational unit.

The manner in which the various trigger pairs are operated incombinations to represent digits of the decimal notation will now beexplained in an operation in which ten impulses are sent to thedenomination to operate it through a complete cycle and return it tostarting condition. As shown in the tabulation given earlier herein, thezero or starting condition of the trigger pairs of the denomination isthat in which all the trigger pairs A, B, C, and D are in off condition,with their right triodes conducting. All input impulses to thedenomination are applied to the coupling device, tube 226, which in turnapplies them to trigger pair A, the first trigger pair of the cascade.

The first impulse applied to trigger pair A changes it from its offcondition to its on" condition, so that the trigger pair A will be onand trigger pairs B, C, and D will be off to represent the digit 1.

The second impulse applied to trigger pair A changes it from on to on.As trigger pair A goes from on to off, it sends an impulse to triggerpair B, which turns trigger pair B from off" to on. At the end of thisentry, trigger pairs A, C, and D are ofi, and trigger pair B is on torepresent the digit 2.

The third impulse applied to trigger pair A merely changes that pairfrom off to on. At the end of this entry, trigger pairs A and B are onand trigger pairs C and D are "off to represent the digit 3.

The fourth impulse applied to trigger pair A turns trigger pair A fromon to oil," and trigger pair A, in turning off, sends an impulse totrigger pair B to turn it from on to off. Trigger pair B, in turningfrom on to off, sends an impulse to trigger pair C to turn it from offto on. At the end of this entry, trigger pairs A, B, and D are off andtrigger pair '0 is "on to represent the digit 4.

The fifth impulse applied ta trigger pair merely turns thistrigger'pairfrom on? tcron,. and, at the end of this entry, triggerpairs A and C will. be on and trigger pairs B and D will. be ofi torepresent the digit 5.

The sixth. impulse applied to trigger pain A wiil? turn this. triggerpair from on to" in. turning from on to ofi,

[LG -,I, trigger A will.

send an impulse to trigger pair B to turn; it from: operation,

Refill Iron?! trigger pairs A pairs B and C digit 6;.

The seventh impulse applied to trigger pair." A. will merely turntrigger pair A from oii to on-,3 and, at the end and. C will be on""andtrigger pair D' will be off to represent the digit 7.

At the end iof this and D will be ofij will be on and triggertorepresent the The eighth impulse appliedto trigger pair A will turn.trigger pair A from on to: o and the turning of trigger pair-A oii.sends an im pulse to trigger pair 3 to turn trigger pair B fromon to oTrigger pair B, in turning off-,7 will send an impulse to trigger pair Cto turn itfrom on. to ofi. turning on, will. send anpair D to turn itfrom "01? i r pair in. impulse to trigger' to on.

more positive, and this is reflected through the: direct-currentfeed-back circuit.- on' the bias of. the: left triodes' of triggerTrigger pair 0;, in turning off, will s'endr an: impulse to: triggerpairD. Triggerpair D- has already been turned to off by the,

impulse from. trigger-pair A, and, as explainedearlier herein,. from.trigger pair 0: will not be effective to turn.- it' o'niag'ain.: At theend of this entry, the trigger pairs A, B, C-and D will be in oncondition, which. is the condition in which they of the entry of the tenimpulses.

It is'seen, therefore, that the four cascaded trigger pairs of thedenominationcan be: oneratedto accumulate values in the tation and bethe application of tenimpulsesto the first trigger pair of the cascadeand can representth'e' various digits 1 to 9 and: "0 of'the accumulatorby combinations of on and. off conditionsof the several trigger pairs.

Higher: denominational orders of the accumu-" lator will be. similar tothat shown in th'e drawing-but' will have a. connection to the grid 01'the of this entry, trigger pairs A;B"

all the; trigger condition, will send an 'B" and; D to: turn: them inturning 0112? will remove the positivebias from the condition, will"send-an impulse: totrigger pair C to: turn it from wereat: thebeginning:

decimal no-" returned to starting condition upon:

' and trigger pair- A,

the pair changes from right. triode of the coupling device from the tenstransfer means of the next lower order to en: able transfer entries tobe made therein when required.

Tens transfer means are provided for the accumulator to make an entryofv a value of one in the next higher denominational order of theaccumulator each time a denominational order exceeds its capacity. Sincethe same type of. transfer means couples adjacent denominational ordersof. the accumulator; the or ierationv of the. various transfer meanswill be" clear trom. a; descriptionof. the operation of the transfermeans: shown in thedrawing for coupling the units and. tens.denominational orders of the accumulator.

The transfer means includes a trigger pair which is. operatedfrom anormal conducting condition: when entries in. the related denominationalcascaded: trigger pairs cause them to exceed their digital capacity-and;is effective to cause an entry in; the next higher order when restored.tonormal condition;

, The: tens transfer trigger pair is shown as being: made up of twohalves of a: twin. triode, tube 3:15, preferably of the above-mentioned2051 384-, of 10p ohms, point 381, and resistor: 3532,v of.

510,000 ohms, and also is coupled to anode 311.

resistor 388, of 390,000 ohms, resistor 383- being shunted by capacitor390, farads.

When the accumulator is initially set inoperation. or is reset to zero;the tens transfer trigger pair is set in its normal condition, lefttriode conducting, as will be explained more of micro-micro considered.

When' a tens transfer is: required. the cascaded trigger pairs of. thedenomination will cause the tens transfer trigger pair to operate itsconducting status.v This. is accomplished in the following manner'. Asisseen from the tabu lation: given earlier herein, the'trigger' pair Dwill; change from its on condition to its off condition only when thedigitrepresented by the cascaded trigger pairs changes-from 9 to 0:

to reverse Thefdr'op across anode resistor M8- of' the right triode of'this trigger pair, whicho'ccurs when as a negative impulse: triod'e" ofthe tens transfer trigger pair, over resistor 392 of'l00,-000- ohms,capacitor 39-3 of 2 5- micro-microfarads, and thetens transfer triggerpair to be operated from its normal condition and reverse the conductingstatus" of its 'trio'des "to store the carry indication until thecarrycan be effected.-

triodes are connected to on to bit, is applied to grid 38!! of the left"Negative potential transfer-effecting impulses are applied overconductor 395 during intervals between digit entries in the accumulator.One source of such impulses is disclosed in the application, Serial No.137,311 of which this application is a division and reference may be hadto that application for details thereof.

The impulses on conductor 395 are transmitted over capacitor 398 of 25micro-microfarads to grid 386 of the ger pair and will restore thetrigger pair to its normal condition to send a transfer impulse to thenext higher order, if the trigger pair had been operated from normalcondition to store a carry during a digit-entering operation. The returnof the transfer trigger pair to its normal condition will mean that theright triode will cease to conduct, and consequently its anode potentialwill become more positive. The potential rise of anode 311 will betransmitted as a +125-volt impulse over resistor 391 of 47,080 ohms,conductor 312 and a capacitor to the grid of the right triode of thecoupling device of the tens denominational order which is not shown butwhich is similar to the coupling device 220 and will cause the entry ofa value of one in the tens denominational order.

It is clear, therefore, that the tens transfer trigger pair will beoperated from normal by its related denomination, when the accumulationin the cascaded trigger pairs has exceeded their digital capacity andthe cascaded trigger pairs have indicated that a carry is required tothe next higher order, and will store the carry indication until the endof the digit entry operation, at which time the first transfer-eifectingimpulse will return any operated tens transfer trigger pairs to theirnormal condition and cause the value of "one to be entered in the nexthigher orders as required. The tens transfer-effecting impulses arecontinuously applied to the transfer means between digit entries, sothat, whenever a tens transfer entry causes a denomination to exceed itscapacity and operate the tens transfer trigger pair from its normalcondition, the following transfer-effecting impulse will be eifective toreturn the trigger pair to its normal condition and cause the requiredtens transfer entry to be made, thereby enabling carry-on-carryoperations to take place.

If the tens transfer trigger pair has not been operated from its normalcondition during the digit entry in its related denominational order,the right triode will be in non-conducting condition and the negativetransfer-effecting impulses, which will be impressed thereon immediatelyafter the digit-entering period, will have no efiect thereon.

In a similar manner, other transfer means can be controlled from thetrigger pairs of their related orders and can be operated bytransfereifecting impulses to cause tens transfer entries to be made inappropriate higher orders.

In order to prepare the accumulator initially to receive entries or toreset it to its zero condition, reset switches, as 261, are provided inthe negative bias supply circuits for the grids of the right triodes ofthe trigger pairs A, B, C, and D of each denominational order. Momentaryopening of the switches will remove negative bias potential from thesegrids and will cause the trigger pairs A, B, C and D to be set in theiroff condition.

The transfer trigger pairs in the various orders are also conditioned bythe operation of the reset right triode of the transfer trigcorrespondsto the positive potential.

switches, which removes negative bias from the grids of the left triodesof these trigger pairs and causes these trigger pairs to be set to theirnormal position, with the left triode conducting. This control of thetransfer trigger pairs from the reset switches insures that thesetrigger pairs will always be set to their normal condition initially orafter a resetting operation, and prevents any improper transfers frombeing made as a result of changing trigger pair D to its off conditionin the initial setting or resetting operations.

Means are provided to manifest the digit values represented by thecombinations of on and "off conditions of the cascaded trigger pairs ofthe various denominational orders of the accumulator.

The means for manifesting digits in the units denominational order isshown in the drawing, and, since the manifesting means for other ordersis the same as this one, their operation will be clear from theexplanation of this one.

Associated with the cascaded trigger pairs of this denominational orderis a set of digit-representing conductors M5, containing a conductor foreach of the digits 1 to 9 and 0. The anodes of the right and lefttriodes of the eascaded trigger pairs are connected through a resistancenetwork selectively to various ones of the digit-representingconductors, the anode 3i! of the right triode of trigger pair D beingconnected over resistors, as 416, of 1.3 megohms to the conductorsrepresenting 6 and 7, and the anodes of the remaining triodes beingconnected over resistors, as Ml, of 2.2 megohms to various ones of thedigit-representing conductors in a pattern which is clearly shown in thedrawing.

Depending upon whether the trigger pairs are on or ofi, the anodepotentials of their left and right triodes will be either at almost +200volts or at a much lower potential as a result of the drop across theanode resistors of the conducting triodes. The pattern of resistancenetwork connections, as shown, is so arranged that, for anydigitrepresented by the combination of on or "off conditions of the cascadedtrigger pairs, the conductor corresponding to that digit will have apotential which is less positive than that of any otherdigit-representing conductor and will thereby manifest the digitstanding in that order of the accumulator. 7

If desired, the potentials of the digit-representing conductors can besensed and can control an apparatus for positioning a digit-bearingwheel with the digit in reading position which conductor having theleast One such mechanism for accomplishing this result is shown in myco-pending application Serial No. 133,540, which was filed on December17, 1949.

In a similar manner, digits represented by the on and off conditions inother denominational orders can be made apparent.

While the form of mechanism shown and described herein is admirablyadapted to fulfill the objects primarily stated, it is to be understoodthat it is not intended to confine the invention to the one form orembodiment disclosed herein, for it is susceptible of embodiment invarious other forms;

What is claimed is:

i. In an apparatus of the class described, the combination of fourelectronic devices, each operable alternately to one and to anothercondition in response to impulses impressed thereon, and

vincluding means to' supply operating and bias 'zpo'tentials to"thefdevices andfitotproducexpotential changes =-each "timeea:Qcle'vicechangestfrom =either condition-to the other; said devices by; their one'and other; conditions; in combination," representing the dig'its 1" to 9an'd"0 circuits connecting-the devices in seriesand ienablingi thepotential change, which 'islproduced whent a device operates to one ofsaid c'onditions,: to be applied-as an impulseto the next device ofiitheseries" to cause an operation thereof means to apply "input impulses toif the "first device of the series,- a J direct-current circuit from the'fourth 'device of I the se'ries to the bias "potential supplies "forthesecond and third deviees to enable 'the fourth-device to control thebi-as second and third devicesto 'cause" them"-to be operatedsimultaneously from the four'th device each time the fourth device -issin -a*eertainone of-said conditions r and means to connect the firstdevice to the fourth device to enable the first device sto :operate.the: fourthszdevice I, OilllaOf': said certain condition.

2. In an apparatus of the class described, the combination of fourtrigger'pairs, each operable to" be-' triggeredalternately-tonne*and toanother condition; means tosupply operating potentials and biaspotentialsto the" trigger pairs circuits connecting thetrigger pairsinsefies forselective operation in response -to-inputimpulses applied tothe' first pairof-the series; means *to couple a portion r'ifthe-biassupply for the second "and third'trigger-pairs of the "seriestothe fourth trigger'pair of the series-toenable the fourth pair tocontrol thebias onxthe-second and third pairs, said fourth pair, when inone-condition, causing the bias'on these'cond'and third airs to be suchas to allow these;pairstojioperate normally. as

trigger pairs, and, whenun the; other condition,

cause them to operate to one of their conditions; and means coupling thefirst and fourth trigger pairs to enable the first pair to operate thefourth pair to said one condition to restore normal trigger pairoperating characteristics to said second and third pairs.

3. In a multi-denominational order apparatus for accumulating values inthe decimal notation, the combination of, for each denominational order,four trigger pairs, each operable to be triggered alternately to one andto another condition; means to supply operating potentials and biaspotentials to the trigger pairs and including means to produce potentialchanges each time the pair changes from either condition to the other;circuits connecting the trigger pairs in series to enable a potentialchange produced by a pair to be applied as an impulse to the next pairof the series to cause its operation, the series connections enablingthe pairs to be operated selectively in combination in response to inputimpulses applied to the first pair of the series; a direct-currentfeed-back circuit to couple a portion of the bias supply for the secondand third trigger pairs of the series to the fourth trigger pair of theseries to enable the fourth pair to control the bias on the second andthird pairs,

cause them simultaneously to make an additional operation to one oftheir conditions; and an additional circuit coupling the first andfourth trigger pairs to enable the first pair to operate the fourthsupplied t "the i pair tot-said oneizcondition to restoremormal1triggerpair op'erating:characteristicsto saidzsecond andwthii'd pairs, said"trigger pairs 1 of :eachwdenominational"ordergwhen controlled by theseries circuits ,:.ther"directecurrent feedeback circuit; and theadditional .'circuit,'-:ioperating to accumulate valuesxzand'itoprogressively:"represent-a thee-digits 0 1and" il":to f9rbycombinationstofrsaid one and said other: conditions.

In aid'evi'ce :for accumulating-values iinaethe idecimallnotation; the;combination :ofzfourepairs of electron'idischarge devices, :each :devicehaving at' leastsan:anode;:a cathode; and. means to. controlconduction;therebetween ;":circuits:'for supplyingioperatingi'potentialsatodthe: devices and foncrossconnecting thedevic'esbfzapair;anode to control meansgto"enableItha devices of: each:pair't'oioperate'iasaitrigger' pairian'd includingtmeangto prolducea-an:impulse for: each :c'hangenin :operating condition idfiilihe'pair,zsachxpairtbeing :ori Icondition' when:conduction'foccursrinoneidevice and; in tfo'fiflxconditioni-when conducticnsoccurs inthesotherzdevice ;.';means connecting the trigger pairs-aim cascade,including arcircuit connecting .thezanoderof :the rather "deviceiofzaf-firstione iof said :trigger zpairs *to :the :conduction c controlmeans :of thadevioes: ofzasecond onelof'said trier egeripairs and totheeoonduction; controlzmeanstof the: one "device: of 2a :fourth "one:of s said trigger pairs, to I enable the impulse,'ziwhichsiscproducedwhen :thei first trigger pair' operat'es from "=on' to "101? condition,toibelapplieditoithe 'second trigger pair" to. causei-aiitriggeroperationith'ereof andto" beaapplied to the; Ffourth trigger; pairflto'turnxit from fion -to" ioff fconditionsifitfhas been turnedto its ioniconditionia.circuiteonnecting theianodexofxthe otheridevice of thesecond'f trig- .ger .pair to; thexsonduhtion icontrol: meansaoffia thirdioneizofssaid .trigger;pairsi toi enable thetiinpulse which is producedeach time the second pair operates from on to off condition, to beapplied to the third trigger pair to cause a trigger operation thereofand a circuit connecting the anode of the other device of the thirdtrigger pair to the conduction control means of the other device of thefourth trigger pair to enable the impulse, which is produced when pairoperates from on to off condition, to be applied to the fourth pair tocause it to operate condition; a direct-current control circuit from theanode of the other device of the fourth trigger pair to the conductioncontrol means of the one device of the second and third trigger pairs toenable the potential of the anode in the different operating conditionsof the fourth pair to modify the bias on the control means of the secondand third trigger pairs and cause these trigger pairs to be turned to oncondition when the fourth trigger pair is on condition; and means toapply input impulses to the conduction control means of the firsttrigger pair; said trigger connections, cascade connections, anddirect-current control circuit enabling the four trigger pairs tooperate and accumulate amounts and progressively represent the digits 0and "1 to 9 by combinations of on and off conditions of the triggerpairs. 5. In a device for accumulating values in the decimal notation,the combination of four pairs vices of each pair to operate as a triggerpair in response to negative impulses, and including means to produce animpulse for each change in operating condition of the pair, each pairbeing in on condition when conduction occurs in one device and in "011condition when conduction occurs in the other device; means connectingthe trigger pairs in cascade, including a circuit connecting the anodeof the other device of a first one of said trigger pairs to theconduction control means of the devices of a second one of said triggerpairs and to the conduction control means of the one device of a fourthone of said trigger pairs, to enable the negative impulse, which isproduced when the first trigger pair operates from on to ofi condition,to be applied to the second trigger pair to cause a trigger operationthereof and to be applied to the fourth trigger pair to turn it from nto off condition if it has been turned to its "on condition, a circuitconnecting the anode of the other device of the second trigger pair tothe conduction control means of a third one of said trigger pairs toenable the negative impulse which is produced each time the second pairoperates from on to off condition, to be applied to the third triggerpair to cause a trigger operation thereof and a circuit connecting theanode of the other device of the third trigger pair to the conductioncontrol means of the other device of the fourth trigger pair to enablethe negative impulse, which is produced when the third trigger pairoperates from on to off condition, to be applied to the fourth pair tocause it to operate from off to on condition; a direct-current controlcircuit from the anode of the other device of the fourth trigger pair tobias potential supply for the conduction control means or the one deviceof the second and third trigger pairs to enable the potential of theanode in the different operating conditions of the fourth pair tocontrol the bias on the control means of the second and third triggerpairs to provide these trigger pairs with a bias that will allow normaltrigger operations when the fourth pair is in "off condition, and toprovide these trigger pairs with a more positive bias that will causethe pairs simultaneously to be turned to on condition when the fourthtrigger pair is in its on condition; and means to apply negative inputimpulses to the conduction control means of the first trigger pair; saidtrigger connections, cascade connections, and direct-current controlcircuit enabling the four trigger pairs to operate and accumulateamounts and progressively represent the digits 0 and 1 to 9" bycombinations of on and off conditions of the trigger pairs. 1

CARL F. BENCH.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,490,500 Young Dec. 6, 1949 2,521,788 Grosdoff Sept. 12, 19502,521,789 Grosdofi Sept. 12, 1950 2,536,955 Palmer Jan. 2, 19512,538,122 Potter Jan. 16, 1951 2,540,924 Bergiors Jan. 30, 19512,562,591 Wagner July 31, 1951 2,577,075 Dickinson Dec. 4, 19512,584,311 Phelps Feb. 5, 1952 OTHER REFERENCES Electronics: A Four TubeCounter Decade," by Potter, pages 110-113, June 1944.

RCA Review, vol. II, No. 3; Electronic Counters, by Grosdofi, pages438-447, September 1946.

